The elastic modulus matrix of an HTI medium with a symmetry axis along
the *x* direction (which I will denote as ) has the
following form (in compressed notation):

(3) |

(4) | ||

From here on, to simplify notation, I use the variables and , introduced by Dellinger 1991. Thus we rewrite equation (4) as

(5) | ||

HTIprop
Definition of propagation
angles. The azimuthal angle is measured with respect to the
symmetry axis, and the incidence angle with respect to the
vertical axis.
Figure 1 |

11/12/1997